A=[sqrt(3) -1; 1 sqrt(3)]
[V,D]=eigs(A)
[p,r]=cart2pol(real(D(1,1)),imag(D(1,1)))
p*180/pi

S=[r 0; 0 r];
p=30*pi/180;
R=[cos(p) -sin(p); sin(p) cos(p)]
S*R
A